Adjustable ring gauge



Aug, 7 T1951 H. n... PETERsN fi fi ADJUSTABLE RING GAUGE Filed Jan. 22, 1947 Patented Aug. 7, 1951 I umTEotsTAr s earrimr OFFICE Harold L. Peterson, Worcester, Mass, assignor to John Bath & Company, Worcester, Mass, a corporation of Massachusettsv Application January 22, 1947, Serial No. 723,604

' 1 y This invention relates to ring gauges and to means for closely adjusting the internal diameter of such gauges. While capable of general application, the invention relates more particularly to ring gauges which are internally threaded and which are to be used to measure screw threads.

It is the general object of my invention to provide improved means for slightly adjusting or varying the internal diameter of such a ring gauge and for securely retaining the adjusted setting.

A further object is to provide an adjustable ring gauge which comprises very few parts and in which the parts are comparatively simple and are relatively inexpensive to manufacture.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claim.

A preferred form of the invention is shown in the drawings, in which Fig. 1 is an enlarged sectional elevation of my improved gauge;

Fig. 2 is an end view of the inner or gauging member;

Fig. 3 is a side elevation thereof, looking in the direction of the arrow 3 in Fig. 2;

Fig. 4 is an end view of a clamping ring;

Fig. 5 is a sectional elevation thereof, taken along the line 55 in Fig. 4;

Fig. 6 is an end view of the outer member or holder;

Fig. 7 is a side elevation thereof; and

I Fig. 8 is a view similar to Fig. 2 but showing a slight modification.

Referring to the drawings, my improved adjustable ring gauge comprises an inner ring or gauge member ID, an outer holder II, and a clamping member I2.

The inner ring It has a cylindrical outer surface 20 and beveled or frusto-conical end surfaces 2I and 22, and is slotted at 23 to permit slight expansion or contraction thereof.

\ The inner surface 24 may be threaded as shown in Fig. 2, if the device is to be used as a thread gauge, or may have a cylindrical opening 1,25 in a gauge member Illa (Fig. 8), if the device is to be used as a plain ring gauge. The inner ember ID or I (la is so constructed that when in \normal or free condition, the internal diame- \of the member will be slightly oversize or \r than the actual diameter for which the is to be used.

outer member or holder II has a cylin- 1 Claim. Cl. 33-178) drical recess 30 to receive the gauge'member is and has an inwardly projecting beveled surface 3| which is engaged by the beveled or conical end surface 2! of the member Ill. The holder II preferably has a knurled outer surface for convenience in handling, as shown in Fig. 7, and is provided with an enlarged and internally threaded recess 32 adapted to receive the clamping ring I2.

The clamping ring I2 is externally threaded at 46.1 to fit the threaded recess 32 in the holder I I, and is provided With an internal cylindrical surface lI, preferably of the same diameter as the recess 3!! in the holder II. The ring l2 also has an inwardly projecting beveled or conical surface 42 adapted to engage the end surface 22 of the inner or gauge member ID.

The clamping ring I2 is preferably provided with holes 54 to receive the studs of a suitable spanner for turning the ring I2 in adjusting the gauge.

My improved ring gauge is easily assembled by placing the member ID in the recess 35 of the holder I I and then applying axial pressure to the member If! by inserting and turning the clamping ring I2. This operation applies endwise pressure to the conical surfaces 2| and 22 of the gauge member Iii. As the gauge member ID is split at 23, such endwise pressure naturally contracts the gauge member until the desired internal diameter is attained. A clamping screw 46 (Fig. 1) may then be tightened to force a loose plug l'l against the surface 48 of the holder I I, thus preventing any possible displacement of the clamping ring I2.

I have thus provided a very simple adjustable ring gauge comprising only a split gauge member Ill, a holder II and a clamping ring I2, all of which parts are of simple construction and may be easily manufactured. Furthermore, the contracting pressure is uniformly applied at both ends of the inner member IE3 and at all points about the periphery of said member, so that uniform contraction is obtained and so that the gauging surface remains an accurate surface of revolution.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claim, but what I claim is:

An adjustable ring gauge comprising a rigid holder having a cylindrical recess with an inwardly projecting frusto-conical flange at one end and with an enlarged and internally threaded recess at the other end, a cylindrical slotted resilient inner gauge member which is normally oversize and which is insertable in said cylindrical recess and which has two frustoconical end surfaces, one of said surfaces having substantial surface-engagement with the corresponding surface of said frusto-conical holder flange, a clamping member threaded in said enlarged recess of said holder and having a frustoconical clamping surface having substantial surface-engagement with the second frustoconical end surface of said inner gauge member, and means to retain said holder and said memher in selected angular relation, the coacting frusto-conical surfaces of said holder, said gauge member and said clamping member reacting to contract said gauge member uniformly to a selected diameter by rotation of said clamping member in said holder in a direction to cause the frusto-conical surfaces of said holder and clamping member to approach each other and 4 to thereby exert contracting pressure on said gauge member.

HAROLD L. PETERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 473,582 Keiper Apr. 26, 1892 664,995 Ernst Jan. 1, 1901 1,282,392 Doonaevski Oct. 22, 1918 1,487,803 Peterson Mar. 25, 1924 1,843,202 Buchanan Feb. 2, 1932 2,000,783 Muller May 7, 1935 FOREIGN PATENTS Number Country Date 353,674 Germany May 23, 1922 850,824 France Sept. 18, 1939 

